Extendable cutting member

ABSTRACT

Provided is a minimally invasive cavity formation instrument for forming tissue cavities. The instrument includes an end effector having an aperture through which a cutting element is laterally extended and retracted. The cutting element may be retracted for minimally invasive insertion into a tissue region and extended to form a tissue cavity. The end effector of the instrument may be articulated or rotated to facilitate cavity formation.

PRIORITY

This application is a continuation of U.S. Non-Provisional patentapplication Ser. No. 12/124,672, entitled “Extendable Cutting Member,”filed May 21, 2008, which claims priority to the disclosures of U.S.Provisional Patent Application Ser. No. 60/939,355, entitled“Articulating Cavitation Device,” filed May 21, 2007, U.S. ProvisionalPatent Application Ser. No. 60/939,365, entitled “Extendable CuttingMember,” filed May 21, 2007, and U.S. Provisional Patent ApplicationSer. No. 60/939,362, entitled “Delivery System and Method for InflatableDevices,” filed May 21, 2007, which are herein incorporated by referencein their entirety.

BACKGROUND

Versions of the present invention relate to restoring the anatomy offractured bone and, more particularly, to restoring the anatomy offractured bone with an inflatable device.

Increasingly, surgeons are using minimally invasive surgical techniquesfor the treatment of a wide variety of medical conditions. Suchtechniques typically involve the insertion of a surgical device througha natural body orifice or through a relatively small incision using atube or cannula. In contrast, conventional surgical techniques typicallyinvolve a significantly larger incision and are, therefore, sometimesreferred to as open surgery. Thus, as compared with conventionaltechniques, minimally invasive surgical techniques offer the advantagesof minimizing trauma to healthy tissue, minimizing blood loss, reducingthe risk of complications such as infection, and reducing recovery time.Further, certain minimally invasive surgical techniques may be performedunder local anesthesia or even, in some cases, without anesthesia, andtherefore enable surgeons to treat patients who would not tolerate thegeneral anesthesia required by conventional techniques.

Surgical procedures often require the formation of a cavity withineither soft or hard tissue, including bone. Tissue cavities are formedfor a wide variety of reasons, such as for the removal of diseasedtissue, for harvesting tissue in connection with a biopsy or autogenoustransplant, and for implant fixation. To achieve the benefits associatedwith minimally invasive techniques, tissue cavities are generally formedby creating only a relatively small access opening in the target tissue.An instrument or device may then be inserted through the opening andused to form a hollow cavity that is significantly larger than theaccess opening.

One surgical application utilizing the formation of a cavity withintissue is the surgical treatment and prevention of skeletal fracturesassociated with osteoporosis, which is a metabolic disease characterizedby a decrease in bone mass and strength. The disease frequently leads toskeletal fractures under light to moderate trauma and, in its advancedstate, can lead to fractures under normal physiologic loadingconditions. It is estimated that osteoporosis affects approximately15-20 million people in the United States and that approximately 1.3million new fractures each year are associated with osteoporosis, withthe most common fracture sites being the hip, wrist, and vertebrae.

An emerging prophylactic treatment for osteoporosis, trauma, or the likeinvolves replacing weakened bone with a stronger synthetic bonesubstitute using minimally invasive surgical procedures. The weakenedbone is first surgically removed from the affected site, thereby forminga cavity. The cavity is then filled with an injectable synthetic bonesubstitute and allowed to harden. The synthetic bone substitute providesstructural reinforcement and thus lessens the risk of fracture of theaffected bone. Without the availability of minimally invasive surgicalprocedures the prophylactic fixation of osteoporosis-weakened bone inthis manner would not be practical because of the increased morbidity,blood loss, and risk of complications associated with conventionalprocedures. Moreover, minimally invasive techniques tend to preservemore of the remaining structural integrity of the bone because theyminimize surgical trauma to healthy tissue.

Other less common conditions in which structural reinforcement of bonemay be appropriate include bone cancer and avascular necrosis. Surgicaltreatment for each of these conditions can involve removal of thediseased tissue by creating a tissue cavity and filling the cavity witha stronger synthetic bone substitute to provide structural reinforcementto the affected bone.

Medical balloons are commonly known for dilating and unblocking arteriesthat feed the heart (percutaneous translumenal coronary angioplasty) andfor arteries other than the coronary arteries (noncoronary percutaneoustranslumenal angioplasty). In angioplasty, the balloon is tightlywrapped around a catheter shaft to minimize its profile, and is insertedthrough the skin and into the narrowed section of the artery. Theballoon is inflated, typically, by saline or a radiopaque solution,which is forced into the balloon through a syringe. Conversely, forretraction, a vacuum is pulled through the balloon to collapse it.

Medical balloons also have been used for the treatment of bonefractures. One such device is disclosed in U.S. Pat. No. 5,423,850 toBerger, which teaches a method and an assembly for setting a fracturedtubular bone using a balloon catheter. The balloon is inserted far awayfrom the fracture site through an incision in the bone, and guide wiresare used to transport the uninflated balloon through the medullary canaland past the fracture site for deployment. The inflated balloon is heldsecurely in place by the positive pressure applied to the intramedullarywalls of the bone. Once the balloon is deployed, the attached cathetertube is tensioned with a calibrated force measuring device. Thetightening of the catheter with the fixed balloon in place aligns thefracture and compresses the proximal and distal portions of thefractured bone together. The tensioned catheter is then secured to thebone at the insertion site with a screw or similar fixating device.

BRIEF DESCRIPTION OF THE FIGURES

It is believed that versions of the present invention will be betterunderstood from the following description taken in conjunction with theaccompanying drawings. The drawings and detailed description that followare intended to be merely illustrative and are not intended to limit thescope of the invention.

FIG. 1 depicts a perspective side view of one version of a trocar andcannula assembly of a vertebral cavity formation and fracture reductionsystem.

FIG. 2 depicts a perspective side view of the trocar of FIG. 1 shownafter removal from the cannula of the assembly.

FIG. 3 depicts a perspective side view of the cannula of FIG. 1 shownafter removal of the trocar from the assembly.

FIG. 4 depicts a perspective side view of one version of a drill that isconfigured for insertion through the cannula of FIG. 3.

FIG. 5 depicts a perspective view of one version of a cavity formationinstrument of a vertebral cavity formation and fracture reduction systemshown in the articulated position.

FIG. 6 depicts a longitudinal, cross-section view of the cavityformation instrument of FIG. 5 shown in the unarticulated position.

FIG. 7 depicts a more detailed view of the longitudinal, cross-sectionview of FIG. 6 showing the handle portion of the cavity formationinstrument.

FIG. 8 depicts a more detailed view of the longitudinal, cross-sectionview of FIG. 6 showing the end effector potion of the cavity formationinstrument in the unarticulated position.

FIG. 9 depicts a more detailed view of the longitudinal, cross-sectionview of FIG. 6 showing the end effector potion of the cavity formationinstrument in the articulated position.

FIG. 10 depicts a perspective side view of one version of a vertebralfracture reduction apparatus of a vertebral cavity formation andfracture reduction system.

FIG. 11 depicts a longitudinal, cross-section view of the vertebralfracture reduction apparatus of FIG. 10.

FIG. 12 depicts a more detailed perspective side view of the accessports and port housing of the vertebral fracture reduction apparatus ofFIG. 10.

FIG. 13 depicts a more detailed perspective side view of the balloon anddelivery tentacle of the vertebral fracture reduction apparatus of FIG.10.

FIG. 14 depicts a transverse, cross-section view of the balloon,delivery lumens, and insertion sheath of the vertebral fracturereduction apparatus of FIG. 10.

FIG. 15 depicts a flowchart of one version of a vertebral cavityformation and fracture reduction method.

FIG. 16 depicts a longitudinal, cross-section view of a medical devicehaving an extendable cutting member coupled with a transition membershown in an extended position.

FIG. 17 depicts a longitudinal, cross-section view of the extendablecutting member of FIG. 16 shown in a retracted position.

FIG. 18 depicts a transverse, cross-section view of the medical deviceof FIG. 16 taken along reference line 3-3 showing the transition member.

FIG. 19 depicts a longitudinal, cross-section view of an alternateversion of a medical device having an extendable cutting member coupledwith a shaft member shown in an extended position.

FIG. 20 depicts a longitudinal, cross-section view of the extendablecutting member of FIG. 19 shown in a retracted position.

FIG. 21 depicts a transverse, cross-section view of a medical devicetaken along reference 3-3 of FIG. 16 illustrating an alternate versionof a transition member.

FIG. 22 depicts a transverse, cross-section view of a medical devicetaken along reference 3-3 of FIG. 16 illustrating an alternate versionof a transition member.

FIG. 23 depicts a longitudinal, cross-section view of an alternateversion of a medical device having an extendable cutting member coupledwith a shaft member shown in an extended position.

FIG. 24 depicts a longitudinal, cross-section view of the extendablecutting member of FIG. 23 shown in a retracted position.

FIG. 25 depicts a perspective side view of a delivery system for aninflatable device.

FIG. 26 depicts a perspective side view of an alternative version of adelivery system for an inflatable device.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 1, disclosed is one version of a trocar and cannulaassembly (10) of a vertebral cavity formation and fracture reductionsystem and method used to access a vertebral body. The assembly (10)includes a trocar (12) and a cannula (14) associated with a composite ortwo-part handle (16). The two-part handle (16) is configured forrotation and includes a first detachable handle portion (18) coupled tothe trocar (12) and a second handle portion (20) coupled to the cannula(14). Rotation of the handle (16) and/or trocar and cannula assembly(10) may be accomplished in any suitable manner such as with manualrotation or with a motor. The handle (16) is shown as being symmetrical;however, any suitable offset or asymmetrical shape is contemplated. Thetwo-part handle (16) has a distal surface (17) that is gripped by auser's fingers and a proximal surface (19) that is gripped by the user'spalm. The distal surface (19) of the two-part handle (16) may have anysuitable surface effect such as, for example, defined finger grips, acurved surface, a generally flat surface, concavities, and/orconvexities. The proximal surface (19) on the first detachable handleportion (18) may include a surface (21) configured to accept a hammerstrike.

The distal tip (25) of the trocar (12) is configured to access andpenetrate the cortical bone of a vertebra, where the vertebra isaccessed with the trocar and cannula assembly (10) engaged. Once thevertebra has been accessed by the distal tip (25) of the trocar (12),the cannula (14) may be urged into the passage formed by the trocar(12). The trocar (12), which may be configured from stainless steel, isremovable from the cannula (14) after accessing the vertebra. Removal ofthe trocar (12) from the assembly (10) leaves the cannula (14) in place,for example, within the cortical wall of the vertebra as an instrumentconduit for the insertion of any suitable instrument or device. In theillustrated version, the trocar (12) is withdrawn from the cannula (14)by removing the first detachable handle portion (18) from the assembly(10) until the trocar (12) is pulled proximally from the cannula (14).The trocar (12) and cannula (14) are shown in more detail in FIGS. 2 and3.

Referring to FIG. 2, one version of the trocar (12) is shown afterremoval from the cannula (14) of the assembly (10). The trocar (12)includes an elongate cylindrical body (22) having a proximal end and adistal end, where the proximal end of the body (22) is coupled with thefirst detachable handle portion (18) and the distal end includes thedistal tip (25), shown in FIG. 1, a first penetration member (24), and asecond penetration member (26). In the illustrated version, the firstdetachable handle portion (18) includes a grip (28) to facilitaterotation of the penetration members (24) and (26) to access the vertebraand create a passage into the vertebra. The grip (28) may also be usedto facilitate decoupling the handle portion (18) from the two-parthandle (16). The handle portion (18) further includes a coupling (30)configured to detachably engage the second handle portion (20)associated with the cannula (14). Uncoupling the handle portion (18)from the handle portion (20) allows the trocar (12) to be removed fromthe cannula (14).

The first penetration member (24) of the trocar (12) is a cylindricalbody having a plurality of intersecting flats, bevels, or faces thatform a point at the distal tip (25) configured to penetrate tissue andvertebral bone with manual rotation and longitudinal articulation. Thefirst penetration member (24) is configured to provide the initialaccess, after an incision is made, through a patient's skin and into thecortical bone of a vertebra. The relatively small diameter of the firstpenetration member (24) facilitates insertion and positioning orrepositioning of the trocar (12). The second penetration member (26) isa transition between the smaller diameter first penetration member (24)and the larger diameter body (22) of the trocar (12) and includes aplurality of flats configured to expand the diameter of the passage. Inone version, the wider second penetration member (26) has sharp edgesthat facilitate cutting of bone. Providing dual diameter or stepped tipsmay ease insertion and improve the stability of the trocar (12). Thestepped penetration members (24) and (26) increase the size of theaccess point to a diameter sufficient to accept the cannula (14) forinsertion and retention within the vertebra.

It will be appreciated that the trocar (12) may be configured with anysuitable features to facilitate vertebral access, skiving, penetrationof cortical bone, or any other suitable use. The trocar (12) may includeone or a plurality of stepped tips, including the first and secondpenetration members (24) and (26), having any suitable cutting effects,diameters, shapes, and/or configurations. The one or a plurality ofpenetration members may be sharp, dull, fluted, or have any othersuitable configuration. The distal end of the trocar (12) may betapered, have movable cutting members, or may be coated or otherwiseassociated with materials, such as diamond, that facilitate cutting.

Referring to FIG. 3, the cannula (14) is shown after removal of thetrocar (12) from the assembly (10) shown in FIG. 1. Generally, thecannula (14) is configured to function as an instrument conduit to theintervertebral space, or any other suitable tissue space, after theinitial access point has been formed and the trocar (12) removed. Thecannula (14) may be retained within the vertebral cortical bone for theduration of the procedure while the second handle portion (20) remainsoutside the patient's body as an access port. The cannula (14) includesan elongate cylindrical body (32) defining a lumen having a proximal endand a distal end, where the proximal end of the body (32) is coupledwith the second handle portion (20) and the distal end includes anaperture (34) through which the trocar (12) and other instruments areconfigured to pass. The second handle portion (20) includes a coupling(36) configured to engage the coupling (30) of the first detachablehandle portion (18), shown in FIG. 2, in a rotating snap fit. The secondhandle portion (20) includes a bore similarly sized and coaxial with thelumen of the cylindrical body (32) to accept instrumentation. Thecannula (14) further includes a grip (37) that facilitates positioningand removal of the cannula (14) once the trocar (12) is removed. Thegrip (37) may be separate and distinct from the distal surface (17) ofthe two-part handle or, alternatively, when the two-part handle (16) iscoupled in the assembly (10) the grip (37) and distal surface (17) mayform a contiguous or substantially contiguous surface. In this manner,the grip (37) and the distal surface (17) may both be used for rotationof the handle (16) to facilitate vertebral access. Providing a two-parthandle having a contiguous grip (37) and distal surface (17) mayfacilitate use of the assembly (10), shown in FIG. 10, while providingeffective gripping surfaces for use of the cannula (14) and trocar (12)separately.

Referring to FIG. 4, one version of a drill (40) is shown that is usedin accordance with a vertebral cavity formation and fracture reductionsystem and method. The drill (40) includes an elongated, stainless steelcylindrical body (42) having a distal end and a proximal end, where theproximal end is coupled to a handle (44) and the distal end isconfigured as a drill bit (46). The body (42) of the drill (40) is sizedto fit through the central lumen of the cannula (14) and, afterintroduction into the cannula (14), the drill bit (46) is used to form,for example, an access passage in the cancellous bone of the vertebra.The handle (44) is provided with a grip (48) to facilitate manualrotation of the drill (40) within the cancellous bone of the vertebra toform a passage up to the anterior cortex. The body (42) is provided withmarkings (50) to indicate the minimum depth required for the insertionof subsequent instruments. Following creation of the access passage, thedrill (40) is configured for removal through the cannula (14). Anysuitable markings (50) may be provided using any suitable metric todetermine proper insertion.

Referring to FIG. 5, disclosed is one version of an articulating cavityformation instrument (100) that may be used to form a tissue cavity in,for example, cancellous bone within a vertebral body. In one version,the cavity formation instrument (100) is approximately 40 cm in lengthand includes, generally, a handle (102), an insertion member, such asinsertion tube (104), and an end effector (106) configured forarticulation. The handle (102) has a generally cylindrical body, havinga proximal end and a distal end, aligned along a first linear axis A-A.The handle (102) includes a body (108) and a series of rotationalactuation members (110), (112), and (114), that are rotatable about thefirst linear axis A-A to articulate various aspects of the end effector(106). In the illustrated version, the rotational members (110) and(112) are knobs secured to the center shaft (128), shown in FIG. 6, andare retained within the body (108) of the handle (102). Rotationalmember (114) is secured to the body (108) of handle (102) by a matingflange. It will be appreciated that the illustrated rotational actuationmembers (110, (112), and (114) are described by way of example only,where any suitable mechanism, such as slides, levers, geared components,or the like, including combinations thereof, may be used to actuate thecavity formation instrument (100).

The insertion tube (104) of the vertebral cavity formation and fracturereduction system extends axially along the first linear axis A-A fromthe distal end of the handle (102) to the proximal end of the endeffector (106). The insertion tube (104) may be stainless steel anddefines an interior lumen having an opening at both ends. In theillustrated version, with particular reference to FIG. 8, a pivot pin(116) is welded to the insertion tube (104), where the pivot pin (116)is transverse to and offset from the first linear axis A-A. As will bedescribed herein, the pivot pin (116) facilitates articulation of theend effector (106) such that it is offset from the first linear axisA-A. The pivot pin (116) is one example of an articulation region of theinstrument (100).

The end effector (106), which has a proximal portion (122) and a distalportion (124), is located at the distal end of the insertion tube (104)and is configured to rotate and articulate relative to the insertiontube (104). The proximal portion (122) of the end effector (106) iscoupled to the insertion tube (104) with the pivot pin (116) such thatthe end effector (106) is restrained from axial movement relative to theinsertion tube (104), but is rotatable about the pivot pin (116). Inthis manner, the end effector (106) can be articulated such that it isoffset from first linear axis A-A into alignment, for example, with thesecond linear axis B-B. The second linear axis B-B is described by wayof example only, where any suitable degree or distance of articulationis contemplated.

The distal portion (124) of the end effector (106) which may be, forexample, from 1.8 cm to 2.8 cm in length, is configured to rotate,relative to the proximal portion (122) of the end effector (106), aboutthe central axis A-A of the end effector (106). The distal portion (124)of the end effector may also be rotated about the second linear axisB-B, or any other suitable offset axis, when the end effector (106) isin an articulated position. Rotation of the end effector (106), in boththe articulated and unarticulated position, facilitates cavity formationby allowing cancellous bone to be cut about or around multiple axes.Providing a wide range of axes about which portions of a cavity can beformed facilitates the creation of a wide range of cavity configurationsthat may provide greater therapeutic effect.

The end effector (106) further includes a lateral aperture (120) and anaperture (134) through which a deformable cutter (118) is extended andretracted. In the illustrated version, the deformable cutter (118) is anelongate, stainless steel flexible band that may be between 1.5 cm to 3cm in length; however, any suitable cutting element such as, forexample, a wire, an energized cutting element, a filament, a cuttingelement having a free end, a cutting element having memory retentionproperties, and/or a cutting element that expands outwardly withrotation may be utilized. Any suitable shape such as oval, triangular,or elliptical is contemplated. In the illustrated version, the distalend of the cutter (118) is fixedly coupled to the end effector (106) andthe proximal end of the cutter is attached via a junction member (132)to a movable shaft (128) configured to rotate and translate within theinsertion tube (14). The cutter (118) is threaded through the aperture(134) in the distal end of the end effector (106) and is fixedly coupledto a more proximal portion of the end effector, as illustrated in FIG.8, to form an expandable and retractable cutter.

FIGS. 6-8 illustrate longitudinal, cross-section views of the cavityformation instrument (100) of the vertebral cavity formation andfracture reduction system and method. FIG. 7 illustrates a more detailedview of the handle (102) and FIG. 8 illustrates a more detailed view ofthe end effector (106). Referring to FIGS. 6 and 7, a central channel(126) is depicted that extends along the first linear axis A-A withinthe body (108) of the handle (102). The proximal end of the insertiontube (114) is affixed within this channel (126) such that the insertiontube (104) and the channel (126) are coaxial. A shaft (128) is providedthat extends from a coupling with the rotational member (114) throughthe interior lumen of the insertion tube (104) to a coupling at thejunction member (132) associated with the distal portion (124) of theend effector (106).

Referring to FIG. 7, the shaft (128) is associated with the rotationalmember (114) such that rotation of the rotational member (114)correspondingly rotates the shaft (128) and the attached distal portion(124) of the end effector (106). Thus, the rotational member (114) isused to rotate the end effector (106) and cutter (118) relative to theinsertion tube (104). In the illustrated version, the rotational member(114) and the shaft (128) are not coupled for axial translation, onlyrotational translation, where axial translation of the shaft (128) isindependent from the operation of the rotational member (114). Therotational member (114) is used to rotate the end effector (106) whenthe cutter (118) is extended to rotationally cut tissue to form a tissuecavity, for example, wholly within a vertebra.

Referring to FIG. 7, the center rotational member (112) is associatedwith the shaft (128) to facilitate expansion and retraction of thecutter (118) through the aperture (134). The rotational member (112) isthreadedly engaged with the shaft (128) in a jack screw configurationsuch that rotational movement of the rotational member (112) istranslated as axial movement to the shaft (128). The shaft (128) isfreely rotatable relative to the rotational member (112) such that onlyaxial motion, and not rotational articulation, is translated to theshaft (128) by the rotational member (112). As discussed previously,rotation of the shaft (128) may be controlled independently by theproximal rotational member (114). The rotation and axial translation ofthe shaft (128), in the illustrated version, are distinct and separateoperations with independent mechanisms to give the cavity formationinstrument (100) operational flexibility.

Referring to FIG. 8, axial translation of the shaft (128) causes thejunction member (132) to urge the proximal end of the cutter (118) in acorresponding proximal or distal direction. Translating the shaft (128)in the distal direction, such as by rotating the rotational member (112)in a first direction, urges the cutter (118) against an abutment (138)and outwardly through the aperture (134), thus expanding the cutteroutwardly to increase the cutting radius. Translating the shaft (128) inthe proximal direction, such as by rotating the rotational member (112)in a second direction, urges the cutter (118) to retract through theaperture (134) and against a transverse member, thus reducing thecutting radius. The rotational member (112), shown in FIG. 7, can beused to adjust the cutting radius of the cavity formation instrument(100) to a desired radius prior to rotating the cutter (118) to form acavity. In an alternate version, the cutter (118) can be extended orretracted simultaneously while rotating the end effector (106) to form acavity.

Referring to FIG. 7, the distal rotational member (110) is associatedwith an articulation drive member (130) to facilitate articulation ofthe end effector from the first linear axis A-A to the second linearaxis B-B, shown in FIG. 9. The rotational member (110) is threadedlyengaged with the drive member (130) in a jack screw configuration suchthat rotational movement of the rotational member (110) is translated asaxial movement to the drive member (130). The distal end of the drivemember (130) is coupled to proximal portion (122), shown in FIG. 8, ofthe end effector (106) with a pin (136). Drawing the drive member (130)and pin (136) proximally causes the end effector (106) to rotate aboutthe pivot pin (116). Articulating the end effector (106) in such amanner allows the end effector to be positioned along a second linearaxis B-B, shown in FIG. 9, offset from the first linear axis A-A. Whenin the offset position, the cutter (118) may be extended with therotational member (112) and rotated with the rotational member (114) toincrease the volume of a cavity. The end-effector (106) is realignedwith the first linear axis B-B by urging the drive member (130) and pin(136) distally.

FIG. 9 illustrates a longitudinal, cross-sectional view of the endeffector (106) shown in the articulated position with the cutter (118)extended. The end effector (106) has been articulated into alignmentwith the second linear axis B-B by axially translating the drive member(130) and rotating the end effector (106) about the pivot pin (116).Articulation of the end effector (106) may occur at any suitablearticulation region or point such as, for example, the pivot pin (116),a geared articulation region, a hinge, a metal hinge, a plasticmaterial, a flexible member, a living hinge in flexible material, ashape memory alloy articulation region, or combinations thereof One or aplurality of articulation regions or points, such as pivot pins (116),may be provided to allow for articulation about multiple planes and/oraxes. Articulation may be mechanical, such as with a pivot pin or ageared configured, in a manner that excludes flexible or living hingecomponents at the articulation point or region. As described in theillustrated version, the drive member (130) is proximally and distallytranslated by rotating the rotational member (110). The cutter (118) isshown in the extended position after the shaft (128) has been urgeddistally by rotating the rotational member (112). In the position shownin FIG. 9, the distal portion (124) of the end effector (106) is rotatedto form a cavity portion about the second linear axis B-B.

Articulation of the end effector (106) allows for an offset cavityportion to be formed while the insertion tube (104) remains aligned withthe first linear axis A-A. The offset cavity portion of theintervertebral cavity facilitates central placement of the balloon(212), which may be advantageous under certain circumstances. Forexample, an offset cavity may be useful depending on the geometry of thebone, in creating an anchor to provide more torque in an asymmetricalcavity, creating an undercut, or for accessing regions of a bone offsetfrom the access point. Creating an offset cavity may allow for largercavities to be created. Generally, the range of cavities and access maybe increased while permitting the instrument to be inserted through arelatively small access point.

Referring to FIG. 10, disclosed is one version of a vertebral fracturereduction apparatus (200) of the vertebral cavity formation and fracturereduction system. The vertebral fracture reduction apparatus (200) isapproximately 32 cm in length and includes, generally, a series offlexible access ports (202), (204), and (206), a port housing (208), aninsertion sheath (210), a central dual lumen (218), a side lumen (220),an inflatable member or balloon (212), and a delivery tentacle (214).The apparatus (200) is configured for insertion into a cut vertebralcavity in a deflated configuration and for expansion within the cavityto reduce a vertebral compression fracture. Once the fracture isreduced, the apparatus (200) is configured to deliver bone cement intothe vertebral cavity to restore the integrity of the vertebra. Anysuitable dimension may be provided where, for example, the apparatus(200) may be any length sufficient to reach a target site withoutinterfering with a fluoroscope.

FIG. 11 illustrates a longitudinal, cross-sectional view of thevertebral fracture reduction apparatus (200) of the vertebral cavityformation and fracture reduction system. FIG. 12 illustrates a moredetailed view of the handle access ports (202), (204), (206), and porthousing (208). FIG. 13 illustrates a more detailed view of the balloon(212) and delivery tentacle (214). FIG. 14 is a cross-sectional view ofthe delivery lumen and insertion sheath. Referring to FIGS. 11 and 12,the aligned access ports (202), (204), and (206) have a coplanarorientation and each include a luer connection configured to engage asingle-plunger delivery syringe. Access ports (202) and (204) areassociated with the central dual lumen (218) and the access port (206)is associated with the side lumen (220). Any suitable type or number ofports may be provided where, for example, the ports may be configured toprevent accidental use of an incorrect syringe or applicator with colorcoding, varying dimensions, varying connections, or the like. Anysuitable delivery apparatus may be used including syringes, screw-typeplungers, push plungers, pistol plungers, pressurized devices, motorizedpumps, or the like.

Referring to FIGS. 10 and 11, in the illustrated version the centraldual lumen (218) is an elongated, semi-rigid cylindrical body that isextruded with bismuth, a radiopaque additive, to facilitatevisualization during surgery. The dual lumen (218) is associated withaccess ports (202) and (204) and extends from the housing (208) throughthe balloon (212) and distally from the end of the balloon. The duallumen (218) passing through the balloon (212) may also be referred to asone version of a tentacle for delivering a flowable material. In theillustrated version, the dual lumen (218) is non-linear and has asubstantially S-shaped or curved distal end about which the balloon(212) is mounted. Substantially linear versions or other orientationsfor the dual lumen (218) are contemplated. With particular reference tothe cross-sectional view of FIG. 14, the dual lumen (218) includes asaline delivery lumen (222) and an adjacent cement delivery lumen (224)in a parallel configuration. The saline delivery lumen (222) is fused atthe distal end just proximal to the distal end and includes one or aplurality of apertures (216) that establish fluid communication with theinternal cavity of the balloon (212). The saline delivery lumen (222)provides fluid communication between the access port (202) and theballoon (212) such that saline delivered through the access port (202)enters, fills, and expands the balloon (212). Similarly, salinewithdrawn through the access port (202) correspondingly deflates theballoon (212). In the illustrated version, saline delivered through theaccess port (202) into the balloon (212) is used solely for ballooninflation and is not released into the vertebra or any other part of thebody. However, saline may be released or delivered into a vertebralbody, for example, to assist is clearing away cancellous bone from thecortical wall.

Although inflation of the balloon (212) is described with reference tosaline, it will be appreciated that any suitable flowable material orfluid, which includes air or gases, may be used to inflate and/ordeflate the balloon (212). For example, bone cement, biologic material,bone growth materials, bone fragments, bone paste, bone gel, saline,saline mixed with radiopaque additives, pressurized air, or combinationsthereof may be utilized. The balloon (212) may be non-porous,semi-porous, or porous where, for example, a porous balloon filled withbone cement may ooze bone cement into a vertebral cavity duringinflation.

It will be appreciated that the dual lumen (218) may have any suitableconfiguration and any suitable number of lumens passing entirely orpartially therethrough. The dual lumen (218) may extend through theballoon (212) as illustrated or, alternatively, the dual lumen (218) maybe adjacent or set apart from the balloon (212). The saline deliverylumen (222) and the cement delivery lumen (224) may be configured asseparate lumens not retained within a single dual lumen (218).Generally, all lumens may be single lumen or multi-lumen tubing, wheremulti-lumen tubing may provide an advantageous drop in internal diameterby sharing a wall. Additional lumens may be provided, for example, forsuction, irrigation, a guidewire, inflation of additional inflatablemembers or cement containers, or for tamping.

Still referring to FIGS. 10, 11, and 14, the cement delivery lumen (224)extends along the length of the dual lumen (218) and terminates in adistal aperture (226) at the distal end of the reduction apparatus(200). The cement delivery lumen (224) is in fluid communication withthe access port (204) such that cement delivered through the access port(204) exits the apparatus (200) at the distal aperture (226). The accessport (204) and cement delivery lumen (224) are configured to deliverbone cement, or any other suitable material, through the reductionapparatus (200) into a vertebral body cavity to, for example, restorethe strength of the vertebra after fracture reduction. In theillustrated version, the access port (204) and the cement delivery lumen(224) are configured in such a manner that instruments, such as tampinginstruments, cannot be inserted into the lumen (224); however, it willbe appreciated that the access ports can be configured to accept tampinginstruments, or the like, to facilitate expelling materials from withinthe lumens, packing materials into the vertebral body, and/or cappingthe access point to the vertebra after inserting filler material.Providing a separate port configured to accept a tamping, capping, orpacking instrument is also contemplated.

Referring to FIGS. 10 and 11, in one version, the side lumen (220) is anelongate PET tube in fluid communication with the access port (206) thatterminates in a delivery tentacle (214). In the illustrated version,there is a single delivery tentacle (214) made from PET that is integraland in fluid communication with the side lumen (220). With particularreference to the cross-sectional view of FIG. 14, the side lumen (220)may be bonded with a UV curable adhesive to the dual lumen (218) and theballoon (212), where both the dual lumen (218) and the side lumen (220)may be surrounded by an elongate sheath (210) that extends from thehousing (208) to just proximate the balloon (212). The dual lumen (218)may be bonded to the sheath (210) with cyanoacrylate. The deliverytentacle (214), which may be the portion of the side lumen (220) thatprojects from the sheath (210), can be bonded to the anterior side ofthe outer surface of the balloon (212) with UV curable adhesive. Thedelivery tentacle (214) includes a plurality of spaced apart aperturesalong the length of the tentacle through which cement is delivered intoa vertebral cavity.

It will be appreciated that the illustrated lumens (218), (210) may bebonded or retained by any suitable means, such as the sheath (210), asillustrated, or any suitable adhesive. The delivery tentacle (214) andside lumen (220) may be a contiguous structure, as shown, or,alternatively, the delivery tentacle may be a separate componentaffixed, coupled, or otherwise attached to the side lumen (220). Theside lumen (220) may be rigid and the tentacle (214) may be flexible,both may be flexible, or both may be rigid or semi-rigid. The deliverytentacle (214) further comprises one or a plurality of tentacles havingany suitable configuration for the delivery of bone cement, dye, gas,filling agent, therapeutic agent, medicament, and/or any other suitablematerial. The delivery tentacle (214) may be provided with one or aplurality of apertures and/or may be constructed from a porous materialfor the delivery of fluid into a vertebra.

Referring to FIGS. 10, 11, and 13, in the illustrated version theballoon (212) is a non-porous PET structure, having a generally uniformwall thickness, positioned near the distal end of vertebral fracturereduction apparatus (200). The balloon (212) is coated with urethane andtungsten powder. Each end of the balloon (212) is bonded to the duallumen (218) to form a fluid-tight seal during inflation. A length of theballoon (212) at each end is bound to the dual lumen with a strap tohelp maintain the integrity of the bond during inflation. Theillustrated balloon (212) has a non-axisymmetric configuration and isnot aligned about any linear axis. The balloon (212) defines a singleinternal cavity and is not compartmentalized. In the illustratedversion, the balloon (212) does not have any internal restraints orexternal restraints that restrain expansion of the balloon. The proximaland distal regions of the balloon (212) have a greater width than thecentral portion of the balloon (212), and each end region tapers towardsthe coupling with the dual lumen (218). The balloon (212) is configuredfor fluid communication with the access port (202) and the salinedelivery lumen (222) such that the balloon (212) may be inflated toreduce a vertebral bone fracture when expanded against cortical boneendplates.

The balloon (212) may be provided with any suitable features or elementsconfigured to restrain, shape, or otherwise configured the balloon (212)including, for example, internal restraints, external restraints,varying wall thicknesses, bands, and/or variations in material. Althoughthe balloon (212) is shown in a non-axisymmetric configuration, theballoon may have an axisymmetric configuration, or any other shape, andmay be aligned along a linear axis. The ends of the balloon (212) may betapered, as shown, or may be inverted or have any other suitableconfiguration. Providing a balloon having a uniform diameter along thelength thereof is also contemplated. Any suitable partial or completecoating in one or a plurality of layers may be utilized includingcoatings that are lubricious, rough for trauma applications, radiopaque,anti-bone growth, non-adhesive, barium, bismuth, PET, materials embeddedin PET, tungsten powder, tantalum, or combinations thereof Additionally,radiopaque coatings may be masked in certain sections to aid invisualization, measurement, trauma, placement, guidance, or the like.Any suitable region, band, design, marking, indicia, or writing may bemasked or otherwise indicated for visualization.

Referring to FIG. 15, disclosed is one version of a method (300) for useof the vertebral cavity formation and fracture reduction system. Themethod comprises Providing a Trocar and Cannula Assembly Step (301) thatincludes providing, for example, the trocar and cannula assembly (10)described with reference to FIGS. 1-3. The method (300) comprisesAccessing a Vertebral Body With the Trocar and Cannula Assembly Step(302). Step (302) includes making a small incision in the skin of apatient and inserting the trocar and cannula assembly (10) through theskin and adjacent a fractured vertebra with, for example, atrans-pedicular approach, a postero-lateral approach, or a trans-sacralaxial bore approach. The vertebra is accessed initially, through, forexample, the pedicle or cortical bone, with the first penetration member(24) of the trocar (12). The first penetration member (24) is configuredwith a small point at the distal end to facilitate the introduction ofthe trocar (12) into the pedicle, or other location, to allow forrepositioning if needed, and to provide control in positioning thetrocar. The small point of the first penetration member (24) is used topenetrate the pedicle until the second penetration member (26) abuts thepedicle. The larger diameter second penetration member (26) is thenbored into the pedicle to form an access point sufficiently large forinsertion of the cannula (14). After the access point is created by thetrocar (12), the cannula (14) is retained within the access point tofunction as an instrument conduit for the duration of the procedure.Steps (301)-(303) are described with reference to a composite trocar andcannula assembly (10); however, it will be appreciated that any suitabletrocar and/or cannula may be used in accordance with versions herein.

With the cannula (14) in place, the method (300) comprises Removing theTrocar from the Cannula Step (303), which includes withdrawing thetrocar (12) proximally from the cannula by uncoupling the two-parthandle (16) and withdrawing the first removable handle portion (18).Removing the handle portion (18) and the attached trocar (12) from thelumen of the cannula (14) leaves behind a hollow lumen through which adrill (40), shown in FIG. 4, a cavity formation instrument (100), shownin FIG. 5, a vertebral fracture reduction apparatus (200), shown in FIG.10, and/or any other suitable instrumentation, may be inserted. Uponremoval of the trocar (12), the cannula (14) is left in place within thevertebra where it will remain for the duration of the procedure. Otherinstruments that may be inserted include a backup cement delivery tube,suction, a biopsy device, a camera, a scope, a bone remover, or a cementstopper.

The step of Providing a Drill Step (304) includes providing a passagecreating instrument, such as the drill (40), which is described withreference to FIG. 4. The step of Drilling an Access Passage in VertebralCancellous Bone Step (305) includes inserting the passage creatinginstrument or drill (40) into the cannula (14) until the drill (40)abuts vertebral bone. In one version, the drill bit (46) of the drill(40) is then manually rotated to form a substantially linear cylindricalpassage into the vertebral cancellous bone up to the anterior cortex.The depth of the passage is measured by the markings (50) on the body(42) of the drill (40) to guide the surgeon in controlling the creationof the passage. In one version, the handle (44) of the drill (40), whichprojects proximally from the second handle portion (20) of the cannula(14), is manually rotated by the surgeon's hand via the grip (48) toform the desired passage. Step (305) further includes removing the drill(40) from the cannula (14) after creation of the passage. It will beappreciated that manual operation of various instrumentation describedherein can be performed with a motor or by other electrical ormechanical means.

The step of Providing a Cutting Instrument Step (306) includes providinga cavity formation instrument or device such as the cavity formationinstrument (100) described with reference to FIGS. 5-9. The step ofPositioning the Cutting Instrument Within the Access Passage Step (307)includes inserting the cavity formation instrument (100) through thelumen of the cannula (14) into the passage created by the drill (40).During insertion, the cavity formation instrument (100) is maintained ina linear position where the end effector (106) is aligned with the firstlinear axis A-A. The flexible cutting element (118) is in the fullyretracted position to minimize the width of the end effector (106)during insertion. The depth and placement of the cavity formationinstrument (100) may be monitored via fluoroscope along with depthmarkings to properly position the end effector (106) within the accesspassage of the vertebra. In one version, the end effector is positionedsuch that it is entirely within the cancellous bone volume of a singlevertebra. It will be appreciated that methods described herein may alsobe used for tissue cavity formation, orthopedic cavity formation, spinalcavity formation, vertebral cavity formation, discectomies, or otherorthopedic or medical procedures.

The step of Laterally Extending a Flexible Cutting Element of theCutting Instrument Step (308) includes laterally extending the cutter(118) away from the end effector (106). In one version, the cutter (118)is laterally extended by manually rotating the rotational member (112)in a first direction. Manual rotation of the rotational member (112)operates as a jack screw to urge the shaft (128) distally. Distaltranslation of the shaft (128), which is coupled with the cutter (118)via the junction member (132), urges the cutter (118) outward throughthe aperture (134). Because, in the illustrated version, the cutter(118) is fixed at one end to a proximal portion of the end effector(106), the cutter (118) is expanded outwardly to form an arcuate shapeas the shaft (128) is urged distally. Step (308) includes laterallyextending the arcuate shape of the cutter (118) a desired distance asdetermined by fluoroscope or by resistance from the access passage.

The step of Cutting a First Vertebral Cavity Portion Step (309) includesforming a cavity within the cancellous bone of a vertebra using thecutting instrument (100). Following Step (308) where the cutter (118) ispartially laterally extended, the end effector (106) may be rotatedabout the first linear axis A-A to cut cancellous bone tissue. In oneversion, the cavity is formed by manually rotating the rotational member(114), which correspondingly rotates the shaft (128) and end effector(106) to cut into cancellous bone. The cavity formed in Step (309) maybe generally axisymmetric about the first linear axis A-A. The cavitymay have a greater width than the drilled access passage. In oneversion, the Steps (308) and (309) are performed simultaneously toextend the cutting element (118) while rotating the end effector (106)to form a cavity. Although described with reference to forming avertebral cavity, it will be appreciated that a cavity forminginstrument described in accordance with methods herein may be used inany suitable orthopedic or medical application such as, for example, toform cavities in long bones or in cardiovascular applications for plaqueremoval. Other applications include vertebral disc applications,neurosurgery, interventional radiology, and pain management.

Step (309) further includes extending the cutter (118) laterally atincrements to form successively larger cavities. The cutter (118), maybe extended as described with reference to Step (308), is used to cut aportion of a cavity as described above. In one version, the cutter (118)is then incrementally extended radially outward via rotation of therotational member (112). The rotational member (114) is then rotated toform a successively larger cavity. The incremental extension of thecutter (118) with subsequent cavity formation via the rotational member(114) is repeated a sufficient number of times to create the desiredcavity. A suitable cavity size is determined via fluoroscope. Duringcavity creation, as the cancellous bone is cut it may be allowed tocollect, gather, or pool within the vertebra, it may be compactedagainst the cortical wall, and/or it may be removed from the vertebra. Asuction device may be provided to remove pieces of bone and/or acompaction device may be provided to compact bone against the corticalwall to clear cancellous bone from the cavity.

The step of Articulating the Distal End of the Cutting Instrument Step(310) includes articulating the end effector (106) of the cuttinginstrument (100) within the cavity formed in accordance with Step (309)such that it is offset from the first linear axis A-A. The end effectormay be offset such that it is aligned with a second linear axis such asaxis B-B. The articulation may occur at one or a plurality ofarticulation points or regions, where the end effector (106), forexample, may be articulated such that it is offset a first distance fromthe axis A-A. The first distance may be achieved by pivoting the endeffector (106), bending the end effector (106), or otherwisearticulating the end effector (106) such that it is offset, pivoted, orspaced apart from the axis A-A. Step (310) includes partially retractingthe cutter (118) such that it is adjacent the end effector (106) priorto articulation. The end effector (106) may then be articulated byrotating the distal rotational member (110) in a first direction asdescribed herein.

In one version, articulation in accordance with Step (310) isaccomplished by incrementally articulating the end effector (106) towardthe opposite side of the intervertebral space of the vertebral body. Therotational member (110) is rotated in a first direction to urge the endeffector (106) such that it is incrementally offset from the firstlinear axis A-A. The rotational member (114) is then rotated to increasethe size of the cavity to provide more space for the articulation of theend effector (106). The rotational member (110) is again rotated in thefirst direction to further articulate the end effector (106)incrementally before again rotating the end effector via the rotationalmember (114). The incremental articulation of the end effector (106)with subsequent cavity formation via the rotational member (114) isrepeated a sufficient number of times, as needed, until the end effector(106) is sufficiently articulated. Alternatively, rotation andarticulation may be performed simultaneously. The end effector (106) isproperly guided by the surgeon to the central position via fluoroscope.Articulating the end effector (106) towards the opposite side of thevertebral body may allow a cavity to be formed that exposes the corticalendplates for direct contact with the balloon (212) during expansion toreduce a vertebral compression fracture. Once positioned, the endeffector (106) may be aligned along a second linear axis B-B angled awayfrom the first linear axis A-A of the insertion tube (104).

The step of Cutting a Second Vertebral Cavity Portion Step (311)includes expanding the cavity portion formed in accordance with Step(309), for example, to expose regions of cortical bone within theintervertebral space. The second cavity portion is formed, in oneversion, by laterally extending the cutter (118) and rotating the cutter(118) in the stepwise manner as described in accordance with Steps (308)and (309) to expose the end plates of the vertebra. Alternatively, thesecan be actuated simultaneously. As with Steps (308) and (309), thecutter (118) may be guided via fluoroscope. Specifically, the formationof the second cavity portion may form a central cavity that exposes theendplates of the vertebral cortical bone that will serve as thefoundation for expansion of the fracture reduction balloon (212).

In one version, as the endplates are exposed, the cutter (118) may forma pocket within the cancellous bone adjacent the anterior wall of thevertebral body. When a fracture reduction procedure is performed withthe patient lying face down, there is a natural tendency for cutcancellous bone to be drawn away from the intervertebral space into theanterior pocket of the cavity. In this manner, the anterior pocket ofthe cavity may be used as a cancellous bone reservoir that obviates theneed for bone compaction or bone removal to access the end plates. Step(311) comprises cutting cancellous bone away from the endplates of avertebra and allowing the cut cancellous bone to collect in the anteriorpocket of the cavity. Cutting away cancellous bone, rather thancompacting the cancellous bone, provides for an exposed cortical surfacethat may be more responsive to more predictable compression forces.Removing as much cancellous bone as possible from the intervertebralbody adjacent the endplates may increase the predictability and controlof the procedure.

Although a method of cutting and collecting cancellous bone isdescribed, it will be appreciated that cancellous bone may be removed,pooled, condensed, and/or compacted to form a cavity or cavity portionin accordance with versions herein. For example, cutting away a portionof the cancellous bone and then compacting a thin region of cancellousbone may act as a seal within the vertebral body to prevent the leakageof bone cement or other fluid. By cutting away a first portion ofcancellous bone, prior to compacting a second region of cancellous bone,sufficient cancellous bone may be removed such that a fracture reductiondevice is sufficiently adjacent the cortical bone of the vertebra toeffectively reduce a fracture. Thus, numerous techniques may be combinedin forming a desired cavity. Multiple accessing, cutting, tamping,compaction, stoppering, curing, removal, suction, and/or expansiondevices may be inserted or otherwise used in any suitable manner ororder.

The step of Articulating the Distal End of the Cutting Instrument Step(312) includes articulating the end effector (106) of the cuttinginstrument (100) in the return direction until it is linearly alignedwith the first linear axis A-A. The end effector (106) is articulatedinto alignment by rotating the distal rotational member (110) in asecond direction. In this manner, the cutting instrument (100) may bereturned to its pre-insertion linear configuration such that it can beeasily removed through the cannula (14). The step of Retracting theFlexible Cutting Element Step (313) includes withdrawing the cutter(118) through the aperture (134) by rotating the rotational member (112)in a second direction. In this manner, the cutter (118) is returned toits pre-insertion retracted configuration such that it can be easilyremoved through the cannula (14). The step of Removing the CuttingInstrument Through the Cannula Step (314) includes removing the cuttinginstrument (100) through the cannula after the cutter (118) has beenretracted and the end effector (106) has been brought into linearalignment with the insertion tube (104). In one version, the cannula(104) is left in place during all Steps in which the cutting instrument(100) is utilized. It will be appreciated that any suitable number ofcavity formation instruments having any suitable configuration may beinserted through the cannula (14). For example, cavity formation deviceshaving a plurality of articulations or joints and/or varying degrees ofarticulation may be utilized. Although the end effector (106) isdescribed as retaining a substantially linear configuration, it will beappreciated that the end effector (106) may have any suitable shape,such as a curved shape, or be deformable such as, for example, from asubstantially linear shape to a curved shape if made from a shape memoryalloy such as a nickel-titanium alloy.

The step of Providing a Fracture Reduction Apparatus Step (315) includesproviding a fracture reduction apparatus such as the fracture reductionapparatus (200) described with reference to FIGS. 10-14. It will beappreciated that Step (315) is described with reference to the reductionof vertebral fractures by way of example only and may be used in anysuitable tissue application. The step of Positioning the FractureReduction Apparatus Within the Cavity Step (316) includes inserting thefracture reduction instrument (200) through the lumen of the cannula(14) into a cavity created by, for example, the cutting instrument(100). Prior to insertion, the balloon (212) may be pleated and foldedin a folding machine or otherwise be provided with a reduced size. Thefolding machine includes two separate sets of jaws having a plurality offingers each, where the first set of jaws heats and pleats the balloon(212) and the second set of jaws folds the balloon (212) by wrapping itaround the central lumen (218). During insertion, the fracture reductionapparatus (200) is maintained in a deflated position to minimize thewidth of the balloon (212) during insertion. In one version, theflexibility of the tentacle (214) during insertion allows for thereduced diameter tentacle (214) to be inserted through a relativelynarrow access passage. The flexibility of the tentacle (214) then allowsfor greater expansion of the tentacle (214) after insertion. The depthand placement of the fracture reduction apparatus (200) are monitoredvia fluoroscope and with depth markings to properly position the balloon(212) within the cavity of the vertebra.

After insertion of the fracture reduction instrument, the substantiallyS-shaped or curved distal end of the dual lumen (218) shown in theillustrated version is projected into the vertebral cavity such that theballoon (212) is centrally located within the cavity. In one version,the balloon (212) is positioned such that, upon expansion, the walls ofthe balloon press against the exposed endplates of the vertebra aftercancellous bone has been removed. Other versions may compact substantialor minimal amounts of cancellous bone. The balloon (212) may beconstructed from flexible but substantially inelastic PET such that theballoon (212) expands only to a predetermined shape regardless of thelevel of inflationary pressure. The balloon (212) may be configured toexpand against the cortical endplates to reduce a vertebral fracture,but not to penetrate the anterior pocket of the cavity into which thecancellous bone may be collected. Thus, in one version, the vertebralendplates are expanded to reduce the vertebral fracture withoutcompacting or removing cancellous bone. Alternative versions mayincorporate removing and/or compacting cancellous bone.

The step of Inflating the Fracture Reduction Apparatus to Reduce aFracture Step (317) includes inflating the fracture reduction element(200), for example, against the exposed endplates of a vertebra toreduce a fracture. In one version, the balloon (212) is expandeduniformly with the introduction of a flowable material, such as saline,via the access port (202). In one version, the flexible but inelasticPET balloon (212) is configured to expand against the endplates of thevertebra without expanding to fill the entire cavity. In this manner,the bone fracture is reduced without compacting the bone retained withinthe anterior pocket of the cavity. After being positioned adjacent theendplates of the vertebra in accordance with Step (316), the balloon(212) is inflated with a syringe by introducing saline solution throughthe access port (202) and saline delivery lumen (222). The inflation ofthe balloon (212) corresponds to the volume of saline delivered throughthe syringe. A surgeon determines sufficient inflation by viewing thefracture reduction apparatus (200) under a fluoroscope and by monitoringthe pressure gauge. Because the balloon (212), in the illustratedversion, is constructed from flexible but substantially inelastic PET,the balloon expands only to its predetermined shape regardless of thelevel of inflationary pressure. The balloon (212) is configured toexpand against the cortical endplates to reduce the fracture, but not topenetrate the anterior pocket of the cavity into which the cancellousbone has collected. Thus, in one version, the vertebral endplates areexpanded to reduce the fracture without compacting or removingcancellous bone.

It will be appreciated that the balloon (212) may, alternatively, havean elastic configuration configured to fully fill a cavity, internal orexternal restraints to define the shape of the balloon, any suitableshape, any suitable radiopaque marker, any suitable surface effect orcoating, any suitable number of chambers, compartments, or layers,and/or any suitable combination of materials or wall thicknesses.Although the balloon (212) has been described with reference tovertebral fracture reduction procedures, it will be appreciated that themethods described herein may be useful in other medical procedures suchas orthopedic or cardiovascular applications. The balloon (212) may beused to compact cancellous bone to form a cavity and/or to form a sealaround cortical bone to prevent bone cement or fluid leakage. Theballoon (212) may be filled or inflated with any suitable material suchas saline, bone cement, gas, dye, and/or any other fluid and may have aporous or non-porous surface. In one version the balloon (212) ispermanently implantable where, for example, the balloon is inflated withbone cement and left within the vertebra.

The step of Delivering Bone Cement Into the Cavity Step (318) includesdelivering any suitable flowable material, such as bone cement, fluid,air, gas, medicament, bone paste, bone pieces, bone growth factor, orthe like, through the cement delivery lumen (224) and the deliverytentacle (214) via access ports (204) and (206), respectively. Flowablematerial is delivered through the access ports (204) and (206) with asyringe that is manually plunged. Following Step (317), where theballoon (212) is inflated, the flowable material is delivered throughthe tentacle (214) to fill a portion of the cavity. As the cavitybecomes filled with bone cement, or any other suitable flowablematerial, the balloon (212) may be gradually deflated in accordance withStep (319) to allow bone cement delivered through cement delivery lumen(224) to fill the void within the intervertebral space. Bone cementdelivered through the tentacle (214) may be allowed to fully set or onlypartially set prior to delivering cement through delivery lumen (224).In one version, flowable material may delivered via the cement deliverylumen (224) and/or the delivery tentacle (214) prior to inflation of theballoon (212), where, for example, bone cement may be delivered via thetentacle (214) prior to inflation and, upon inflation, the bone cementis urged into any cracks that may be present in cortical bone.

Step (318) further includes delivering multiple successive layers of amaterial, such as bone cement, to the inner surface of a vertebralcavity. For example, a layer of bone cement may be delivered through thetentacle (214) and allowed to set for a predetermined period of time.Multiple successive layers of bone cement, therapeutic materials,fluids, or the like, may then be provided within the vertebral cavity.One or a plurality of layers or coatings may be delivered with thefracture reduction element (200) and/or other delivery instruments.

The step of Deflating the Fracture Reduction Apparatus Step (319)includes partially deflating the fracture reduction apparatus (200) suchthat bone cement can be delivered into the cavity. The balloon (212) ofthe fracture reduction apparatus (200) is deflated by withdrawing thesyringe associated with access port (202) to draw fluid out of theballoon (212). Removing fluid with the syringe decreases the volume ofsaline within the balloon and creates a vacuum within the balloon thathelps with retraction. Step (319) further includes fully deflating theballoon after a sufficient amount of bone cement has been delivered inaccordance with Step (319). Step (319) further comprises mechanicallywrapping the balloon (212).

The step of Removing the Fracture Reduction Apparatus Through theCannula Step (320) includes removing the fracture reduction apparatus(200) after the balloon (212) has been substantially deflated and thecavity has been filled with bone cement. While the balloon (212) ismostly removed from the vertebra, bone cement is delivered through thecement delivery lumen (224) to fill the cavity. In this manner, the bonecement is able to fill the cavity while the vertebra is being compressedoutwardly to cement the vertebra with the fracture reduced. The fracturereduction apparatus (200) is then removed through the cannula (14). Thestep of Removing the Cannula Step (321) includes removing the cannula(14) from the vertebral body after the vertebral fracture has beenreduced and bone cement injected. Step (321) includes removing thecannula (14) from the patient's body. Step (321) may further includeinserting a stopper device through the cannula (14), prior to removal ofthe cannula, that prevents bone cement or filler material from escapingfrom the vertebral cavity before beginning to set. Once the material ispartially set, the stopper device and cannula (14) may be removed.

FIGS. 16-24 depict alternative versions of the end effector (106) of thecutting instrument (100), shown in FIGS. 5-7 and 9, utilizing agenerally band-shaped cutting element. Alternative versions describedherein utilize shape-changing cutting elements configured to form ormodify cavities in either hard or soft tissue including, for example,cancellous bone within a vertebra. The shape-changing behavior enablesthe cutting instrument (100) to be inserted into tissue through arelatively small access opening to form a tissue cavity having adiameter larger than the diameter of the access point. Thus, versionsdescribed herein may be particularly useful in minimally invasivesurgery, and may be used for at least the following specificapplications, among others: (1) treatment or prevention of bonefracture, (2) joint fusion, (3) implant fixation, (4) tissue harvesting(especially bone), (5) removal of diseased tissue (hard or soft tissue),(6) general tissue removal (hard or soft tissue), (7) vertebroplasty,and (8) kyphoplasty. Tissue cavities created in accordance with versionsdescribed herein may be of any suitable size, shape, or configurationincluding a spherical cavity, a hemispherical cavity, a linear cavity, agroove, a channel, a cavity having varying geometries, such as an upperhemispherical chamber and a lower linear cavity, or any other suitablecavity configuration. Articulation of the alternative versions of theend effector (106) may allow for numerous cavity configurations to becreated along multiple axes and/or planes.

FIG. 16 shows one version of an end effector (406) that may used, forexample, with the cutting device (100) shown in FIG. 5. It will beappreciated that the term “end effector” can refer, generally, to theworking end of the cutting instrument or to an identifiable component ofthe cutting instrument. For example, the end effector (406) may becoupled with the insertion tube (104), shown in FIG. 5, or may be partof a contiguous insertion tube. The end effector (406) includes a shaft(428), a flexible cutting element (418), a transverse member (416), suchas a guide, pin, or catch, and a transition member (432). In theillustrated version, the shaft (428) has a longitudinal axis A-A and agenerally circular cross-section. It will be appreciated that anysuitable cross-section, such as a generally square cross-section, agenerally elliptical cross-section, or a polygon cross-section arecontemplated. In the illustrated version, the end effector (406)includes an aperture (434), where the flexible cutting element (418) isconfigured to be housed or retained at least partially within the endeffector (406).

In the illustrated version, the flexible cutting element (418) is formedfrom a flexible material, such as stainless steel, and is coupled at afirst end (422) to the end effector (406) at about the proximal end ofthe aperture (434). The flexible cutting element (418) is coupled at asecond end (424) to a distal face of the transition member (432).Couplings may be laser welds or any other suitable connection. Theflexible cutting element (418) may be coupled at or near the proximalend of the end effector (406), where a portion of the flexible cuttingelement (418) may be curled under the proximal lip of the end effector(406), as is shown with reference to end effector (106) in FIG. 9, toform a living hinge that diminishes the stress placed upon the flexiblecutting element (418) when deformed. The flexible cutting element (418)may be a flexible band, a cylinder, a ribbon, a serrated element, orhave any other suitable configuration. The flexible cutting element(418) may have a uniform cross-section or varying cross-section.

The transition member (432) is configured to translate along the axisA-A such that axial motion relative to the end effector (406) may betranslated to the flexible cutting element (418) to project the flexiblecutting element (418) laterally through the aperture (434). Thetransition member (432) may be slidable along a track (426) of the endeffector (406) such that rotational movement of the transition member(432) relative to the end effector (406) is restricted. For example,referring to FIG. 18, which is a cross-sectional view of the endeffector (406) taken along line 3-3, the transition member (432) mayhave a wide base (436) to prevent such rotational movement. Thetransition member (432) may have any suitable shape configured torestrict rotational movement relative to the end effector (406) whileallowing axial movement such that the flexible cutting element (418) maybe deformed or laterally extended.

Still referring to FIG. 16, the shaft (428) is distally coupled to aproximal face of the transition member (432) and is connected proximallyto an actuator, such as those described with reference to the cuttingdevice (100) shown in FIGS. 5-9. The shaft (428) is configured toactuate the transition member (432) proximally and distally to deformthe flexible cutting element (418). A rigid or flexible shaft (428) mayextend along the axis A-A and may be fixedly coupled with the transitionmember (432). Proximally, the shaft (428) may be associated with anysuitable actuator configured to provide axial movement including, forexample, actuators and actuation mechanisms described in co-pending U.S.patent application Ser. No. 11/600,313, which is herein incorporated byreference in its entirety. Such actuators may include knobs, slides,T-rails, spools, gear assemblies, triggers, manual actuation, electricalactuation, or the like.

In FIG. 16, the flexible cutting element (418) is shown in an expandedposition configured to form a cavity in, for example, cancellous bonetissue of a vertebra. The expanded position may be formed by distallyactuating the shaft (428) with an actuator such that the transitionmember (432) urges the flexible cutting element (418) against a ramp orinclined portion (430) that may be integral with the end effector (406).The inclined portion (430) may be integrally formed with the endeffector (406), may be an insert, or may otherwise be suitablyconfigured to guide the flexible cutting element (418) laterally throughthe aperture (434) as axial compression force is applied along the axisA-A. As the shaft (428) is actuated axially in a generally distaldirection, the flexible cutting element (418) will correspondinglydeform laterally through the aperture (434). The transition member (432)may be actuated distally until a stop (435) is abutted along the track(426).

In one version, the flexible cutting element (418) is configured toextend from the proximal end to the distal end, or past the distal end,of the end effector (106), where the working length of the cuttingelement (418) may comprise substantially the full length of the endeffector (406). A long working length may increase the cuttingeffectiveness and efficiency of the cutting element (418). Wrapping orcurling one end of the flexible cutting element (418) around theproximal end of the end effector (406), such as illustrated in FIG. 16,may maximize the working length of the cutting element (418) while alsoproviding a living hinge that biases the cutting element (418) outward.The flexible cutting element may also be curled around a portion of thedistal end of the end effector as shown in FIG. 23.

When extended laterally, partially or fully, the flexible cuttingelement (418) may be used to form a cavity by rotating the end effector(406). The end effector (406) may be rotated by a second actuationmember such as, for example, the rotational member (114) of the cuttingdevice (100) shown in FIG. 5. For example, the transition member (432)may be configured such that rotation is translated to the end effector(406), where rotation of the transition member (432) via the shaft (428)correspondingly rotates the end effector (406). In such a manner, theshaft (428) may be used to deform the flexible cutting element (418) andto rotate the flexible cutting element (418) to form a cavity.Rotational and axial motion of elements of the cutting device (100) maybe provided by one or a plurality of actuators as described herein.

Referring to FIG. 17, the flexible cutting element (418) of the endeffector (406) may be deformed to a retracted position for insertion,for example, into a pilot hole in a vertebra, or for removal through aminimally invasive insertion point or cannula upon completion of aprocedure as described, for example, with reference to FIG. 15. In theretracted position, the shaft (428) and the transition member (432) areurged in a generally proximal direction such that the flexible cuttingelement (418) is withdrawn through the aperture (434). In theillustrated version, the flexible cutting element (418) is drawn about acatch or transverse member (416) to achieve a substantially controlledand uniform retraction. When retained against the transverse member(416), the flexible cutting element (418) may be tensioned in theretracted position until the shaft (428) is actuated distally. Thetransverse member (416), in the illustrated version, is a cylindricalbar fixed to the sides of the end effector (406) perpendicular to theaxis A-A. The transverse member (416) is configured such that theflexible cutting element (418) is slidable thereabout. The transversemember (416) is one version of a catch that may have any suitable shape,where the transverse member need not be directly perpendicular to theaxis A-A. The transverse member (416), particularly when configured asillustrated in FIG. 8, may help prevent the cutting element (418) frombuckling during actuation. In particular, the bottom curved surface ofthe transverse member may resist buckling.

Referring to FIGS. 19-20, an alternate version of an end effector (506)is shown where the flexible cutting element (518) is coupled directlywith the shaft (528). The flexible cutting element (518) may be deformedas described above; however, the shaft (528) may be rotatable relativeto the end effector (506). Rotation of the end effector (506) may beachieved via the shaft (528) by rotating the shaft (528) until theflexible cutting element abuts the aperture (534) and further rotationof the flexible cutting element correspondingly rotates the end effector(506). It will be appreciated that the flexible cutting element (518)may be contiguous with the shaft (528).

Referring to FIGS. 21-22, alternate versions of transition elements,taken along a line similar to that of line 3-3 of FIG. 16, are shown incross-section. It will be appreciated that versions of the transitionelements described herein may have any suitable configuration such as atoothed cylindrical transition element (550) guided within acorresponding keyed channel (552) of an end effector. As shown thetransition element (550) may track within a chamber or lumen (554)separate from an adjacent chamber or lumen (556) which may be used, forexample, as a suction or irrigation channel. Referring to FIG. 22, thetransition element may be a toothed projecting transition element (560)configured to slide within a corresponding channel (562). Any suitableslide or tracking configuration is contemplated. It will be appreciatedthat the blade or cutting member may also be keyed or otherwiseconfigured to track within the end effector.

FIGS. 23-24 illustrate an alternate version of an end effector (606)wherein proximal actuation of a transition member (632) with a shaft(628) expands a flexible cutting element (618) through an aperture (634)in the end effector (606). One end of the flexible cutting element (618)may be fixed to the distal end of the end effector (606) and the otherend may be coupled with the transition member (632). With reference toFIG. 24, distal actuation of the transition member (632) draws theflexible cutting element (618) into contact with a guide pin (616), orother restrictive member, such that the flexible cutting element (618)is retracted into the end effector (606). It will be appreciated thatany suitable configuration using a guide pin, or other guide member, iscontemplated. Altering the position of the guide pin or member, such astowards the proximal or distal ends of the aperture, may alter thearcuate shape of the flexible cutting element and provide variousdesirable cutting shapes for medical procedures. As has been describedherein, the end effector (606) may be articulated, actuated, and/orrotated by any suitable means such as, for example, the cutting device(100), shown in FIG. 5, a T-handle, or a power drill.

Version of the flexible cutting element may have a bias toward a“remembered” shape, be configured from a material having a thermalresponse, have a curvilinear shape when expanded, have a waveformconfiguration when expanded, or may otherwise be suitably configured.The memory retention aspects of a number of materials, such as Nitinolor stainless steel, allow for a wide range of possible configurationsthat are contemplated. Shape may be determined or varied depending onthe hardness, material, response to temperature, flexibility, and/orother properties of the cutting elements provided.

For example, a first cavity portion may be created with a flexiblecutting element having a first configuration. After completion of thefirst cavity portion, the flexible cutting element may be changed,deformed, or transitioned to a second configuration to change orincrease the size of the first cavity to form a second cavity. It iscontemplated that a user may alternate between shapes, configurations,and directions while creating a cavity without removing the cavitationdevice from the vertebral body. Configurations from Nitinol, forexample, may be predetermined such that a user may select a predictableshape from a selection such that the user knows precisely which shape isbeing used to cut tissue. It will be appreciated that the shapes may bediscreetly selectable configurations or, in an alternate version, may bepoints along a continuum that may be selected during or prior to aprocedure. Providing a plurality of selectable configurations and/orallowing a user to adjust the configurations of the cutting element maypermit more precise cavity creation or modification.

Versions of the flexible cutting element may be configured, articulated,or manipulated into any suitable shape such as, for example, an arcuateshape, a plateau shape, a curvilinear shape, a coiled shape, a helicalshape, a laterally extended shape, a convex shape, a concave shape, alinear shape, and/or a sinusoidal or wave-shape. The shaft portion maybe integral and contiguous with the flexible cutting element or may be amore clearly defined or discreet actuation member coupled with theflexible cutting element. The distal end of the flexible cutting elementmay be permanently fixed to an insertion tube, such as with a laserweld, such that the distal end remains static as the shaft is tensioned,rotated, compressed, articulated, and/or otherwise moved to change theflexible cutting element from a first shape to a second shape. The shaftand/or the insertion tube may be rotated in a clockwise and/orcounterclockwise direction to form or modify a desired cavity.

In addition to being rotatable or movable in one or a plurality ofdirections, the flexible cutting elements may be provided with one or aplurality of surface effects to create different cutting effects.Multiple cutting edges or surface effects may be combined in a singleflexible cutting element to affect tissue differently depending upon thedirection of cut. The term “surface effect” shall refer to any geometry,feature, projection, texture, treatment, edging, sharpening, tapering,material type, hardness, memory retention, heat treating, response toheat, roughness, smoothness, sharpness, shape, and/or configuration ofone or a plurality of surfaces, faces, edges, points, or the like, ofthe flexible cutting element or any other component of a cavitationdevice. Any suitable surface effect is contemplated including, but notlimited to, serrations, waves, convexities, concavities, edging, points,sharpened edges, smooth edges, rounded edges, flat edges, hardenededges, or combinations thereof It is further contemplated that a firstsurface effect may be provided on a first cutting surface and a secondsurface effect may be provided on a second cutting surface of a flexiblecutting element such that varying the direction of rotation varies thetype of cut or tissue effect.

Any suitable cross-section of the flexible cutting element may beprovided, where altering the shape, size, and/or configuration of theflexible element may advantageously alter the cutting effect, thestiffness, the sharpness, and/or other properties of the flexiblecutting element. It will be appreciated that the illustrated versionsare disclosed by way of example only and are not intended to belimiting. Varying the cross-sections of the flexible cutting elementalong the length thereof may provide advantageous tissue effects and/ormay be structurally advantageous.

Referring to FIGS. 25-26, disclosed are alternative versions of aninflatable device, such as may be used with the fracture reductionapparatus (200) shown in FIG. 10, for use in orthopedic proceduresdirected, for example, towards restoring the anatomy of diseased orfractured bone. Any suitable bone, such as a vertebra, may be prepped byproviding a cavity therein in accordance with devices and methodsdescribed herein. Pre-existing cavities or pre-formed cavities, such asnatural cavities formed within bones, may also be utilized. As has beendiscussed, an inflatable device, such as a balloon, may then be insertedinto the cavity. Once introduced, the inflatable device may be unfoldedand/or inflated through the application of air, gas, fluid, a liquidmatrix, bone paste, bone cement, bone matrix, or the like, via a lumenfluidly connected thereto. The terms “inflate” and “inflation” shallrefer to distention with fluid and/or gas, an increase in volume,swelling, dilation, and/or expansion. The inflatable device may then beinflated intramedullarily with one of a plurality of lumens to applyoutward pressure to the interior surface of the fractured bone.

Thus, the versions of inflatable balloons may be particularly useful inminimally invasive surgery and may be used for at least the followingspecific applications, among others: (1) treatment or prevention of bonefracture, (2) joint fusion, (3) implant fixation, (4) tissue harvesting(especially bone), (5) removal of diseased tissue (hard or soft tissue),(6) general tissue removal (hard or soft tissue), (7) vertebroplasty,and (8) kyphoplasty.

Referring to FIG. 25, an inflatable device (700) is shown having adelivery lumen (712) associated therewith and a plurality of deliverylumen, tubes, tentacles, or projections (714), where the projections(714) are independently filled or inflated from the inflatable device(700) via a delivery lumen (716) and are configured to deliver flowablematerial, bone cement, or other material, through pores (718), holes,slots, apertures, or the like, therein. In one version, the pores (718)are configured to deliver material to a predetermined location, wheremultiple apertures and the location of the tentacle help deliver cementin multiple locations at the same time along the anterior surface of thebody. In this manner flowable material can be delivered to desirableregions, such as the anterior surface of the body, and can be directedaway from less desirable regions such as, for example, the posteriorside of the body.

The tentacles or projections (714) may be made of any suitable materialsuch as balloon material, semi-rigid material, short segments of rigidmaterial, tacky material, memory retention material, adhesive material,rigid material, elastomeric material, and/or any other suitablematerial. The tentacles or projections (714) may be used to deliver anysuitable material including the addition of an adhesive, bone matrix,bone paste, bone cement, synthetic paste, therapeutic agent, healingagent, structural agent, or other suitable material, may assist or speedthe healing process, assist in fitting the balloon properly, provide adye or visual marker or the like to visually identify the position ofthe balloon in a bone through scans or x-ray, provide structuralsupport, or serve any other suitable purpose. Any suitable number ofchambers for any suitable purpose are contemplated. Projections (714),tentacles, or the like, may then be pressurized or sized via theassociated lumen (716) to a desirable pressure, size, configuration,shape, or the like, for the delivery of a particular material. Anysuitable number of projections (714) may be used to deliver material atany suitable location.

Tentacles or projections (714), which include tubes, rigid tubes,semi-rigid tubes, lumens, flexible lumens, bars, spines, protuberances,extensions, support members, combinations thereof, or the like, may beinserted into, attached to, affixed to, coupled with, or formedintegrally with the inflatable device (700), such as the fracturereduction apparatus (200) shown in FIG. 10, in a linear configuration,in a non-linear configuration, in an annular configuration, in a lateralconfiguration, in a longitudinal configuration, in a wave-shapedconfiguration, in a random configuration, in a non-linear configuration,in a threaded configuration, and/or in any other suitable configuration.The tentacles or projections (714) may be coupled with, for example, theinner or outer surface of the inflatable member. Delivery of materialsmay be independent of the inflatable device (700) or combined with theinflatable device. The projections (714), or the like, may project inany suitable direction or manner, such as outwardly from the inflatabledevice or inwardly towards the centroid of the balloon (700).

Additionally, the tentacles or projections (714) may be provided withmultiple chambers, cavities, lumens, tubes, or the like configured toperform various functions. The projections may include a porous outersurface that is connected to a delivery lumen, where an adhesive or thelike may be administered. Individual projections may be inflatable andmay, for example, further include concentric or concatenated chambers.

Referring to FIG. 26, a plurality of tentacles or projections (814) maybe used to deliver material, such as bone cement, via one or a pluralityof corresponding delivery lumens (816), as illustrated, in conjunctionwith a balloon (800). In such a manner, different materials may bedirected to different projections. A single tentacle or projection (814)may be associated with a single delivery lumen (816), multipleprojections (814) may be associated with a single delivery lumen (816),and/or multiple projections (814) may be associated with multipledelivery lumens (816). Multiple delivery lumens (816) may be connectedto a single delivery source or to a plurality of delivery sources andmay be utilized simultaneously or at different times. In an alternativeversion, the tentacle may be a sheath, lumen, or tubing that completelyor substantially covers the outer surface of the balloon (800) where,for example, the sheath may have apertures that can be pumped out and/orforced out when the sheath is compressed against cortical bone.

The versions presented in this disclosure are examples. Those skilled inthe art can develop modifications and variants that do not depart fromthe spirit and scope of the disclosed cavitation devices and methods.Thus, the scope of the invention should be determined by appended claimsand their legal equivalents, rather than by the examples given.

What is claimed is:
 1. A cutting apparatus comprising: (a) a handle; (b)an insertion tube, the insertion tube being associated with the handle;(c) an end effector, the end effector being associated with theinsertion tube, wherein the end effector further includes; (i) a body,the body having a proximal portion and a distal portion; (ii) anaperture formed in the body; (iv) a cutting member, the cutting memberincluding an elongated portion having a first end and a second end,wherein the first end of the cutting member is coupled with the body;and (d) an elongate shaft, the shaft being associated with the secondend of the cutting member, wherein the shaft is associated with thecutting member such that distally translating the shaft urges thecutting member outward through the aperture of the end effector andproximally translating the shaft retracts the cutting member into theaperture.
 2. The apparatus of claim 1, wherein the shaft is coupleddirectly with the second end of the cutting member.
 3. The apparatus ofclaim 1, wherein the cutting member is an elongated member selected fromthe group consisting of a flexible member, a semi-flexible member,semi-rigid member, a band, a polymer member, a metal member, a shapememory alloy member, a nickel-titanium alloy member, an aluminum member,a carbon steel member, a titanium member, a stainless steel member, andcombinations thereof.
 4. The apparatus of claim 1, wherein the endeffector further comprises a transition member, wherein the transitionmember couples the shaft with the second end of the cutting member. 5.The apparatus of claim 4, wherein the transition member is guided by atrack.
 6. The apparatus of claim 4, wherein the transition member isguided by a keyed channel.
 7. The apparatus of claim 4, wherein thetransition member prevents rotation of the shaft relative to the endeffector.
 8. The apparatus of claim 1, wherein the end effector isconfigured to articulate and rotate.
 9. The apparatus of claim 1,wherein the first end of the cutting member is curled around theproximal end of the end effector.
 10. The apparatus of claim 1, whereinthe working length of the cutting member is substantially the length ofthe end effector.
 11. A cutting apparatus comprising: (a) a handle; (b)an insertion tube, the insertion tube being associated with the handle;(c) an end effector, the end effector being associated with theinsertion tube, wherein the end effector further includes; (i) a body,the body having a proximal portion and a distal portion; (ii) anaperture formed in the body, the aperture having a proximal end and adistal end; (iii) a cutting member, the cutting member including anelongated portion having a first end and a second end, wherein thecutting member is at least partially retained within the body; and (d)an elongate shaft, the shaft being associated with the second end of thecutting member, wherein the shaft is associated with the cutting membersuch that proximally translating the shaft urges the cutting memberoutward through the aperture of the end effector and distallytranslating the shaft retracts the cutting member into the aperture. 12.The apparatus of claim 11, wherein the shaft is coupled directly withthe second end of the cutting member.
 13. The apparatus of claim 11,wherein the cutting member is an elongated member selected from thegroup consisting of a flexible member, a semi-flexible member,semi-rigid member, a band, a polymer member, a metal member, a shapememory alloy member, a nickel-titanium alloy member, an aluminum member,a carbon steel member, a titanium member, a stainless steel member, andcombinations thereof.
 14. The apparatus of claim 11, wherein the endeffector further comprises a transition member, wherein the transitionmember couples the shaft with the second end of the cutting member. 15.The apparatus of claim 14, wherein the transition member is guided by atrack.
 16. The apparatus of claim 14, wherein the transition member isguided by a keyed channel.
 17. The apparatus of claim 14, wherein thetransition member prevents rotation of the shaft relative to the endeffector.